This invention relates to explosive severance means and particularly to an explosive linear cutter for separating a target material by propelling a high velocity fragment of metal sheath surrounding an explosive core against the target along a separation line.
Explosive actuators wherein an elongated core of explosive material is detonated for separating a device from a missile upon command are known. Many known actuators employ a core of explosive material within an expandable sheath which does not rupture in order to contain the gaseous products of the explosion and prevent contamination of the surrounding region. One such explosive actuator is described in U.S. Pat. No. 3,373,686 granted jointly to myself and A. B. Leaman. Other explosive actuators are described in U.S. Pat. Nos. 3,698,281; 3,661,084; 3,486,410; 3,336,868 and 3,357,356. Some of these known explosive actuators or severance means use shaped charged or grooves in the target material to weaken it at the desired fracture point. When a MDF is mounted adjacent weakening grooves the explosive force goes in all directions and blows the missile skin apart at the groove locations. The Super Zip produces a very broad cutting path with no contamination. The FLSC produces a cut and rupture of the target material with an attendant blast and debris characteristic similar to the MDF but both fail to provide the desired highly directional cutting mechanism with minimum fragmentation and debris contamination required for clearly severing a composite or laminated skin such as high temperature graphite/borite fiberglass materials useful in re-entry bodies. Moreover, the installation of an FLSC is a problem since it must be oriented precisely, otherwise its reliability goes down. Where composite materials are employed as the missile skin or target to be severed, weakening grooves cannot be used, and the MDF undirected explosive force is not sufficiently strong to rupture the composite material reliably.
A very serious problem has arisen in attempting to clearly cut a laminated or composite missile skin made of fibre materials, such as high temperature graphite/borite fiberglass materials for re-entry bodies. Known cutting or separation actuators such as the MDF (mild detonating fuse), the FLSC (flex-linear shaped charge), and the Super Zip (exemplified by the foregoing patents) U.S. Pat. Nos. 3,373,686 and 3,698,281 have proven unsatisfactory in attempts to very cleanly cut a composite missile skin.
An object of the present invention is to enable the clean separation of a composite skin or laminated body of graphite/fiberglass material with minimum debris and contamination.
Another object is to utilize an MDF explosive core in a modified surrounding metallic tube containing an elongated slot therein registering with a desired severance or separation line, to thereby optimize the explosive force through the slot and generate a very clean highly directional cut in a target material.
A further object is to propel a high velocity fragment of metal through a relatively narrow slot to achieve a clean linear cut in a target.
Other objects and advantages of the invention will appear from a reading of the accompanying description.